Speed Control Device for Speed Changing Device of Bicycle

ABSTRACT

A speed control device, which is adapted to be used in connection with a derailleur type bicycle or internal gear hub type bicycle, has one operation mode for up-shifting the speed and another operation mode for down-shifting the speed. The two operation modes can be affected by an operation lever, and with the operation lever being pivoted in a second rotation direction for the up-shifting operation and in a first rotation direction for the down-shifting operation.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to a speed control device, andmore particularly, this invention relates to a speed control devicewhich facilitates the operation of a speed changing device of a bicycle.

2. Description of the Related Art

U.S. Pat. Nos. 5,213,005, 5,361,645, 5,479,776 and 6,220,111 disclose aspeed control device including one operation lever that user can use toup-shift the speed and another operation lever to down-shift the speed.However, such speed control device has the disadvantage that theoperator could easily operate the wrong lever in a speed changeoperation.

U.S. Pat. No. 5,287,766 shows a speed control device which utilizes anoperation lever for up-shifting and down-shifting the speed. The speedcontrol device is particularly mounted on a straight handlebar typebicycles. In spite of the advantage of speed control device employingone operation lever as discussed in the proceeding, it is believed thatthere is a need for improvement in the field of speed control device andmore specifically in the curved handlebar type bicycles.

The present invention is, therefore, intended to obviate or at leastalleviate the problems encountered in the prior art.

SUMMARY OF THE INVENTION

According to the present invention, the main purpose is to provide aspeed control device, which is adapted to be used in connection with aderailleur type bicycle or internal gear hub type bicycle, has oneoperation mode for up-shifting the speed and another operation mode fordown-shifting the speed. The two operation modes can be affected by anoperation lever, and with the operation lever being pivoted in a secondrotation direction for the up-shifting operation and in a first rotationdirection for the down-shifting operation.

The control assembly is adapted to effect multiple speed change in onestroke of the second engaging mechanism.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a speed control device according to thepresent invention.

FIG. 2 is an exploded perspective view of the speed control device ofFIG. 1.

FIG. 3 is an exploded perspective view of a control assembly embodyingthe present invention.

FIG. 4 is another exploded perspective view of the control assemblytaken from a different angle than that of FIG. 3.

FIG. 5 is a side view of the control assembly embodying the presentinvention.

FIG. 6 is a cross-section view taken along line 6-6 of FIG. 5.

FIG. 7 is a cross-section view taken along line 7-7 of FIG. 5.

FIG. 8 is a cross-section view taken along line 8-8 of FIG. 5.

FIG. 9 is an extended view of FIG. 6 and shows an operation lever of thecontrol assembly is pivoted in a second rotation direction to effect onespeed change.

FIG. 10 is an extended view of FIG. 8 and shows the operation lever ofthe control assembly is pivoted in the second rotation direction toeffect one speed change.

FIG. 11 an extended view of FIG. 7 and shows the control assembly in aposition corresponding to FIG. 10.

FIG. 12 is an extended view of FIG. 10 and shows the control assemblyaccomplishing one speed change.

FIG. 13 is an extended view of FIG. 6 and shows the operation lever ofthe control assembly is pivoted in the second rotation direction toeffect three speed changes.

FIG. 14 is an extended view of FIG. 8 and shows the operation lever ofthe control assembly is pivoted in the second rotation direction toeffect three speed changes.

FIG. 15 is an extended view of FIG. 7 and shows the control assembly ina position corresponding to FIG. 14.

FIG. 16 is an extended view of FIG. 13 and shows the control assemblyactuating a three speed change.

FIG. 17 is an extended view of FIG. 15 and shows the control assembly ina position corresponding to FIG. 16.

FIG. 18 is an extended view of FIG. 16 and shows the operation lever ofthe control assembly is pivoted in a first rotation direction to effectanother speed change.

FIG. 19 is an extended view of FIG. 17 and shows a first angular stepwhich is between a first engaging section and a corresponding tooth.

FIG. 20 is an extended view of FIG. 19 and shows the first engagingsection engaged with the corresponding tooth.

FIG. 21 is an extended view of FIG. 20 and shows a second angular stepwhich is between a second engaging section and a corresponding tooth.

FIG. 22 is an extended view of FIG. 21 and shows the second engagingsection is engaged with the corresponding tooth.

FIG. 23 is an extended view of FIG. 22 and shows a pawl is engaged witha next tooth.

FIG. 24 is a cross-section view taken alone line 24-24 of FIG. 1.

FIG. 25 is an extended view of FIG. 24 and shows a brake lever ispivoted toward a first end of a housing.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

A speed control device according to the preferred teachings of thepresent invention is shown in FIGS. 1-25 of the drawings. The speedcontrol device is adapted to be used in connection with a speed changingdevice of a bicycle. According to the preferred form shown, the speedcontrol device includes a housing 1 defining a first end 101 and asecond end 102 opposite to the first end 101, and the first end 101 isadapted to connect to the bicycle. The housing 1 includes a compartment11 in which a control assembly 2 and a brake assembly 5 are pivotallyreceived. The control assembly 2 is retained in the compartment 11 viatwo fasteners 13, and the fasteners 13 are respectively inserted throughtwo apertures 12 in the housing 11 and engaged in the control assembly2. The control assembly 2 includes a fixing member 20 installed to thehousing 1, a first engaging mechanism 30 pivotally connected to thefixing member 20, and a second engaging mechanism 40 pivotally connectedto the fixing member 20.

The fixing member 20 includes a body 21, a first pawl device 22selectively engaged with the first engaging mechanism 30, and a secondpawl device 23 selectively engaged with the first engaging mechanism 30.The body 21 has two fixing holes 211 corresponding to the apertures 12of the housing 11 and inserted by the fasteners 13, respectively. Thebody 21 further has a first side 212 and a second side 213 opposite toand parallel to the first side 212.

The first side 212 has a first shaft 214 extending therefrom, a firstconnected portion 215 and a second connected portion 216 extendingtherethrough and adjacent to the first shaft 214. Additionally, thefirst shaft 214 includes a first coupling section 2141 on one endthereof distal from the first side 212, and a first rotating section2142 defined between the first coupling section 2141 and the first side212. The first coupling section 2141 has an outer periphery which has anon-circular cross section.

The second side 213 has a second shaft 217 extending therefrom. Thesecond shaft 217 includes a second coupling section 2171 on one endthereof distal from the second side 213, and a second rotating section2172 defined between the second coupling section 2171 and the secondside 213. The second coupling section 2171 has an outer periphery whichhas a non-circular cross section.

The first pawl device 22, which is disposed to the first connectedportion 215 of the body 21, includes a first rod 221 and a first pawl222. The first rod 221 includes a proximal end installed to the firstconnected portion 215, and a distal end mounted by a first orifice 2221of the first pawl 222. The second pawl device 23, which is disposed tothe second connected portion 216, includes a second rod 231 and a secondpawl 232. The second rod 231 includes a proximal end installed to thesecond connected portion 216, and a distal end of mounted by a secondorifice 2321 of the second pawl 232.

The fixing member 20 includes a first retaining unit 24 installedthereto, and a second retaining unit 25 installed thereto. The firstretaining unit 24 has a retaining hole 241 inserted by the firstcoupling section 2141 of the first shaft 214. The second retaining unit25 has a retaining hole 251 inserted by the second coupling section 2171of the second shaft 217. The first 241 and second 251 retaining holeshave shapes conforming to the first 2141 and second 2171 engagingsections where the first 24 and second 25 retaining units are mounted.Therefore, the first 24 and second 25 retaining units are connectedrigidly and prevented from rotation with respect to a longitudinal axisof related first 214 and second 217 shafts, respectively.

The first engaging mechanism 30 includes a cable-receiving member 31, afirst toothed member 32 and a second toothed member 33. Additionally,the cable-receiving member 31, which is adapted to receive a shiftingcable that is adapted to cause speed change upon operation of the speedcontrol device, includes a retaining section 314 on which an end of theshifting cable is secured, and a groove 315 formed on its outerperiphery and provided for preventing a length of the shifting cablewhich is engaged with an outer periphery of the cable-receiving member31 from dislodging therefrom. Specifically, the cable-receiving member31 is rotatable in a first rotation direction R1 to up-shift the speedand a second rotation direction R2 to down-shift the speed. Each of thecable-receiving member 31, first 32 and second 33 toothed members has ahole 311, 321 and 331, respectively, and the holes 331, 321 and 331,which are inserted by the first shaft 214, has a diameter not less thanthat of the first shaft 214. Each of the cable-receiving member 31,first 32 and second 33 toothed members further has at least one pinhole312, 322 and 332 adjacent to related hole 331, 321 and 331,respectively, and the pinholes 312, 322 and 332 are coaxial with eachother. The first engaging mechanism 30 includes at least one pin 34 andan biasing member 35. The pin 34 inserts through the pinholes 312, 322and 332 of each of the cable-receiving member 31, first 32 and second 33toothed members such that the cable-receiving member 31, first 32 andsecond 33 toothed members are rigidly connected to rotation. The biasingmember 35 includes a proximal end engaging to a limiting portion 242 ofthe first retaining unit 24, and a distal end engaging to a limitingportion 313 of the cable-receiving member 31 of the first engagingmechanism 30. Preferably, the limiting portion 242 and 313 are in formof holes. So, if the cable-receiving member 31 is rotated in the firstrotation direction R1 such that the biasing member 35 is tensioned,releasing the biasing member 35 from tension would cause thecable-receiving member 31 to rotate in the second rotation direction R2.

The first toothed member 32 includes a retaining toothed section 323formed on its outer periphery and including a plurality of teeth, inwhich each tooth are asymmetric or the two sides of each tooth are notequal. Preferably, each tooth extends substantially toward the firstrotation direction R1, and two adjacent teeth have a root formedthereon. The second toothed member 33 includes a first toothed section333 corresponding to the first pawl 222, and a second toothed section334 corresponding to the second pawl 232. Each of the first toothedsection 333 and the second toothed section 334 is formed on an outerperiphery of the second toothed member 33 of the first engagingmechanism 30 and includes a plurality of teeth, respectively, in whicheach tooth are asymmetric or the two sides of each tooth are not equal.Preferably, each tooth extends substantially toward the first rotationdirection R1.

The first pawl 222 has a first engaging section 2222 formed on one endthereof, and a first abutted section 2223 formed on the other endthereof and extending toward the second face 213 of the body 21. Thebody 21 has an aperture 218 formed between the first 215 and second 216connected portions, in which the first abutted section 2223 insertsthrough the aperture 218 and protrudes out of the body 21. The firstpawl 222 is biased by a first biasing element 223. Preferably, the firstbiasing element 223 is a torque spring having a first leg extendingtherefrom and connecting to the first abutted section 2223 of the firstpawl 222, and a second leg extending therefrom and connecting to thebody 21 so that the first engaging section 2222 is biased to disengagefrom the first toothed section 333 of the second toothed member 33. Thesecond pawl 232 has a second engaging section 2322 formed on one endthereof distal from the second orifice 2321, and a second abuttedsection 2323 formed between the second orifice 2321 and the secondengaging section 2322 and extending toward the second face 213 of thebody 21. The second abutted section 2323 protrudes out of the body 21.The second pawl 232 is biased by a second biasing element 233.Preferably, the second biasing element 233 is a torque spring having afirst leg extending therefrom and connecting to the second abuttedsection 2323 of the second pawl 232, and a second leg extendingtherefrom and connecting to the body 21 so that the second engagingsection 2222 is biased to engage with the second toothed section 334 ofthe second toothed member 33. The teeth of the first toothed section 333have an arrangement like that of the teeth of the second toothed section334, however, the first 333 and the second 334 toothed sections have aphase shift between them such that the first engaging section 2222 ofthe first pawl 222 and the second engaging section 2322 of the secondpawl 232 would not engage with related tooth of each of the first 333and second 334 toothed sections, simultaneously.

The second engaging mechanism 40 includes a catching member 41, acontrol plate 42 and an engagement plate 43. Each of the catching member41, the control plate 42 and the engagement plate 43 is mounted to thesecond rotating section 2172 of the second shaft 217. The control plate42 is disposed adjacent to the second side 213 of the body 21, theengagement plate 43 is disposed adjacent to the second retaining unit25, and the catching member is disposed between the control plate 42 andthe engagement plate 43. The catching member 41 has a mounting portion411 mounted to the second rotating section 2172 of the second shaft 217,and a catching portion 412 adapted to connect to a operation lever 44 ofthe second engaging mechanism 40. The mounting portion 411 includes afirst side 4111 adjacent to the second side 213 of the body 21, a secondside 4112 opposite from the first side 4111, and a central bore 413extending from the first side 4111 to the second side 4112. The centralbore 413 is mounted to the second rotating section 2172 of the secondshaft 217 such that the catching member 41 is able to rotate withrespect to the second shaft 217 of the body 21. The first side 4111 ofthe mounting portion 411 has a first emboss 414 formed thereon andadjacent to the catching portion 412, and the first emboss 414 extendstoward the second side 213 of the body 21. The second side 4112 of themounting portion 411 has a second emboss 415 formed thereon and adjacentto the catching portion 412, and the second emboss 415 extends away fromthe second side 213 of the body 21. The operation lever 44 is pivotallycoupled to the catching portion 412 via a fastener 45. Preferably, thefastener 45 in a form of a pin is inserted through a support hole 4121of the catching portion 412 and a pivotal hole 441 of the operationlever so as to prevent the operation lever 44 from detaching from thecatching member 41, and the operation lever 44 is pivoted from itscontrol end 442 to pivot the catching member 41. Moreover, the operationlever 44 is biased by a biasing element 46, which is disposed betweenthe catching member 41 and the operation lever 44.

The control plate 42 has a disk portion 421 and an arm portion 422extending from the disk portion 421. The disk portion 421 has a hole 423formed thereon and mounted to the second shaft 217 of the body 21 suchthat the engagement plate 43 is able to rotate with respect to thesecond shaft 217 of the body 21. The second engaging mechanism 40further includes a clutching device 47, which is disposed to the armportion 422 of the control plate 42 and is selectively engaged with thefirst engaging mechanism 30. The clutching device 47 has a rod 471, apawl 472 and a biasing element 473. The rod 471 includes a proximal endinstalled to the arm portion 422 of the control plate 42, and a distalend mounted by an orifice 4721 of the pawl 472. The pawl 472 has anengaging section 4722 and a engaging surface 4723 which are formed onone end thereof, in which the engaging section 4722 and the engagingsurface 4723 correspond to the toothed section 323 of the first toothedmember 32 and a block 21 a of the body 21, respectively. The pawl 472 isbiased by a biasing element 473. Preferably, the biasing element 473 isa torque spring and includes a plurality of coaxially disposed coiledsections inserted by the rod 471 and a first leg extending therefrom andengaging to the control plate 42, and a second leg extending therefromand connecting to the pawl 472 where between the orifice 4721 and theengaging section 4722 so that the engaging section 2222 is biased toengage with the toothed section 323 of the first toothed member 32. Thearm portion 422 has an abutted surface 4221 corresponding to the firstemboss 414 of the catching member 41.

The second engaging mechanism 40 includes an biasing member 48 whichincludes a proximal end engaging to a limiting portion 219 of the body21, and a distal end engaging to a hook 424 of the control plate 42 sothat the abutted surface 4221 of the engagement member 42 is biased toabut against the first emboss 414 of the catching member 41. Preferably,the limiting portion 219 is in form of a hole. So, if the control plate42 is rotated in the second rotation direction R2 such that the biasingmember 48 is tensioned, releasing the biasing member 48 from tensionwould cause the control plate 42 to rotate in the first rotationdirection R1.

The engagement plate 43 includes a hole 431, which extends therethroughand is mounted to the second rotating section 2172 of the second shaft217, an abutted surface 434 corresponding to the second emboss 415 ofthe catching member 41, and a first protrusion 432 and a secondprotrusion 433, which protrude from an outer periphery thereof The first432 and second 433 protrusions correspond to the first abutted section2223 of the first pawl device 22 and the second abutted section 2323 ofthe second pawl device 23, respectively. The first protrusion 432 has afirst portion 4321 distal from the second protrusion 433 and a secondportion 4322 adjacent to the second protrusion 433. Moreover, the firstportion 4321 and a center of the hole 431 has a distance therebetweensmaller than that between the second portion 4322 and the center of thehole 431. The second protrusion 433 has a first portion 4331 adjacent tothe first protrusion 432 and a second portion 4332 distal from thesecond protrusion 432. Moreover, the first portion 4331 and the centerof hole 431 has a distance therebetween smaller than that between thesecond portion 4332 and the center of the hole 431.

The second engaging mechanism 40 includes an biasing member 49 whichincludes a proximal end engaging to a limiting portion 252 of the secondretaining unit 25, and a distal end engaging to a limiting portion 435of the engagement plate 43 so that the abutted surface 434 of theengagement plate 43 is biased to abut against the second emboss 415 ofthe catching member 41. Preferably, the limiting portions 252 and 435 isin form of a hole. So, if the engagement plate 43 is rotated in thefirst rotation direction R1 such that the biasing member 49 istensioned, releasing the biasing member 49 from tension would cause theengagement plate 43 to rotate in the second rotation direction R2.

Particularly, while the operation lever 44 is not operated by a user,the catching member 41 is in a rest position as shown in FIGS. 6 through8, i.e., the first abutted section 2223 of the first pawl 222 is abuttedby the first portion 4321 of the first protrusion 432 such that thefirst engaging section 2222 of the first pawl 222 is disengaged from thefirst toothed section 333 of the second toothed member 33, and thesecond abutted section 2323 of the second pawl 232 is abutted by thefirst portion 4331 of the second protrusion 433 such that the secondengaging section 2322 of the second pawl 232 is engaged with relatedtooth of the second toothed section 334 of the second toothed member 33.The second pawl 232 is engaged with the second toothed section 334 ofthe second toothed member 33 so that the first engaging mechanism 30would not rotate with respect to the first shaft 214 of the body 21 inthe first rotation direction R1. Moreover, the first engaging mechanism30 is engaged with the biasing member 35 so that the first engagingmechanism 30 would not rotate with respect to the first shaft 214 of thebody 21 in the second rotation direction R2 via an elastic force of thebiasing member 35. Therefore, the control assembly would not up-shift ordown-shift the speed while the catching member is in the rest position.

The speed control device 100 has two operation modes. In one operationmode, i.e. the cable-winding operation as shown in FIGS. 9 through 12,the operation lever 44 of the second engaging mechanism 40 is pivotedfrom its control end 442, but not necessary, in the second rotationdirection R2 to pivot the catching member 41 to abuts against thecontrol plate 42 via the first emboss 414 and then cause rotation of thecontrol plate 42, and as the control plate 42 is rotated the firstengaging mechanism 30 is rotated concurrently due to that the engagingsection 4722 of the pawl 472 of the clutch device 47 is engaged with thetoothed section 323 of the first toothed member 32. The engagement plate43 is rotated via the second emboss 415, and as the engagement plate 43is rotated, the first abutted section 2223 disengages from the firstprotrusion 432 of the engagement plate 43 and engages with a holdingsurface 2181 of the aperture 218, in which the holding surface 2181 ofthe aperture 218 and the center of the hole 431 smaller than that of thefirst portion 4321 of the first protrusion 432 so that the firstengaging section 2222 and the first toothed section 333 has a gap toprevent the second toothed member 33 from interfering with respect tothe first engaging section 2222. In addition, the second engagingsection 2322 of the second pawl 232 is shifted from a beginning positionin which the second engaging section 2322 is engaged with a tooth of thesecond toothed section 334 to a first position in which the secondengaging section 2322 is engaged with the next tooth if one speed changeis to be made. The first engaging mechanism 30 is abutted by the secondpawl 232 and the biasing member 35, respectively, so that the firstengaging member 30 is prevented from rotating with respect to the firstshaft 214.

And next, the operation lever 44 is returned to its home position, i.e.an initial position where the operation lever 44 is positioned beforecommencing this cable-winding operation (as shown in FIG. 6). Thecontrol plate 42 is rotated in the first rotation direction R1 by thebiasing member 48, and the abutted surface 4221 abuts the first emboss414 of the catching member 41 to rotate the catching member 41 in thefirst rotation direction R1 such that the engaging section 4722 of thepawl is shifted from a beginning position in which the engaging section4722 is engaged with a root in the toothed section 323 of the firsttoothed member 32 to a first engaging position in which engaging section4722 is engaged with the next root. The second emboss 415 of thecatching member 41 abuts the abutted surface 434 of the engagement plate43 such that the engagement plate 43 is rotated in the first rotationdirection R1 until the operation lever 44 is returned to its homeposition. The first portion 4321 of the first protrusion 432 abuts thefirst abutted section 2223 of the first pawl 222 and the first portion4331 of the second protrusion 433 abuts the second abutted section 2323of the second pawl 232 while the operation lever 44 is in its homeposition.

Additionally, the control assembly 2 is adapted to effect multiple speedchange in one stroke of the operation lever 44 of the second engagingmechanism 40. The body 21 has a retaining surface 21 b formed thereonand adjacent to the block 21 a. The operation lever 44 is able to bepivoted in the second rotation direction R2 from the home position to amaximum pivotal position that the engaging section 4722 of the pawl 472abuts the retaining surface 21 b of the body 21 to prevent the secondengaging mechanism 40 from further rotating in the second rotationdirection R2. FIGS. 13 through 17 show that the operation lever 44 ispivoted to the maximum pivotal position in the second rotation directionR2 to pivot the catching member 41 to abutted against the control plate42 via the first emboss 414 and then cause rotation of the control plate42, and as the control plate 42 is rotated the first engaging mechanism30 is rotated concurrently due to that the pawl 472 of the clutch device47 is engaged with the toothed section 323 of the first toothed member32. Preferably, the control assembly 2 is able to effect three speedchange in one stroke of the operation lever 44 while the operation lever44 is pivoted to the maximum pivotal position in which the secondengaging section 2322 of the second pawl 232 is shifted from thebeginning position to a second position in which the second engagingsection 2322 skip across three teeth and is engaged with the last teethif three speed change is to be made. The first engaging mechanism 30 isabutted by the second pawl 232 and the biasing member 35, respectively,so that the first engaging member 30 is prevented from rotating withrespect to the first shaft 214.

And next, the operation lever 44 is returned to its home position, thecontrol plate 42 is rotated in the first rotation direction R1 by thebiasing member 48, and the abutted surface 4221 abuts the first emboss414 of the catching member 41 to rotate the catching member 41 in thefirst rotation direction R1 such that the engaging section 4722 of thepawl is shifted from a beginning position to a second engaging positionin which engaging section 4722 skip across three roots and is engagedwith the last root. The second emboss 415 of the catching member 41abuts the abutted surface 434 of the engagement plate 43 such that theengagement plate 43 is rotated in the first rotation direction R1 untilthe operation lever 44 is returned to its home position.

In another operation mode, i.e. the cable-releasing operation, as shownin FIGS. 18 through 23, the operation lever 44 of the second engagingmechanism 40 is pivoted in the first rotation direction R1 for thecable-winding operation and is then released to accomplish thecable-releasing. Specifically, the operation lever 44 is pivoted fromits control end 442 in the first rotation direction R1 to pivot thecatching member 41 to abut against the engagement plate 43 via thesecond emboss 415 and then cause rotation of the engagement plate 43.The control plate 42 is rotated in the first rotation direction R1 bythe biasing member 48, and the engaging surface 4723 of the pawl 472 isabutted by the block 21 a of the body 21 so that the engaging section4722 of the pawl 472 is disengaged from the toothed section 323 of thefirst toothed member 32. As the engagement plate 43 is rotated, thefirst protrusion 432 of the engagement plate 43 slides with respect tothe first abutted section 2223 until the first abutted section 2223engages with the second portion 4322 of the first protrusion 432, andthe second protrusion 433 of the engagement plate 43 slides with respectto the second abutted section 2323 until the second abutted section 2323engages with the second portion 4332 of the second protrusion 433. Thesecond engaging section 2322 is disengaged from the second toothedsection 334 of the second toothed member 33 while the second abuttedsection 2323 engages with the second portion 4322 of the firstprotrusion 432, in addition, the first engaging section 2222 is engagedwith a corresponding tooth of the first toothed section 333 of thesecond toothed member 33 while the first abutted section 2223 engageswith the second portion 4322 of the first protrusion 432. Moreover,because the first 333 and the second 334 toothed sections have a phaseshift therebetween, once the second engaging section 2322 is disengagedfrom the second toothed section 334 of the second toothed member 33, thefirst engaging section 2222 is engaged with the corresponding tooth ofthe first toothed section 333 of the second toothed member 33immediately, and the second toothed member 33 is rotated with a firstangular step A in the first rotation direction R1 via the biasing member35, simultaneously, and then the second engaging section 2322corresponds to a next tooth of the second toothed section 334 of thesecond toothed member 33.

And next, the operation lever 44 is returned to its home position, theengagement plate 43 is rotated in the second rotation direction R2 bythe biasing member 49, and the abutted surface 434 abuts the secondemboss 415 of the catching member 41 to rotate the catching member 41 inthe second rotation direction R2 such that the first protrusion 432 ofthe engagement plate 43 slides with respect to the first abutted section2223 until the first abutted section 2223 engages with the first portion4321 of the first protrusion 432, and the second protrusion 433 of theengagement plate 43 slides with respect to the second abutted section2323 until the second abutted section 2323 engages with the firstportion 4331 of the second protrusion 433. The first engaging section2222 is disengaged from the corresponding tooth of the first toothedsection 333 of the second toothed member 33 while the first abuttedsection 2223 engages with the first portion 4321 of the first protrusion432, in addition, the second engaging section 2322 is engaged with thenext tooth of the second toothed section 334 of the second toothedmember 33 while the second abutted section 2323 engages with the firstportion 4322 of the first protrusion 432. Moreover, because the first333 and the second 334 toothed sections have a phase shift therebetween,once the first engaging section 2222 is disengaged from thecorresponding tooth of the first toothed section 333 of the secondtoothed member 33, the second engaging section 2322 is engaged with thenext tooth of the second toothed section 334 of the second toothedmember 33 immediately, and the second toothed member 33 is rotated witha second angular step B in the first rotation direction R1 via thebiasing member 35, simultaneously, and then the first engaging section2222 corresponds to a next tooth of the first toothed section 333 of thesecond toothed member 33 if one speed change is to be made. As thecatching member 41 rotates in the second rotation direction R2, thecontrol plate 42 is rotated in the second rotation direction R2 due tothat the abutted surface 4221 is abutted by the first emboss 414 of thecatching member 41 until the operation lever is back to the homeposition, such that the engaging section 4722 of the pawl 472 is engagedto a corresponding tooth of the toothed section 323 of the first toothedmember 32.

The operation lever 44 is biased by the biasing element 46 as shown inFIG. 25. Preferably, the biasing element 46 is a torque spring andincludes a plurality of coaxially disposed coiled sections inserted bythe fastener 45 and a first leg extending therefrom and engaging to thecatching portion 412 of the catching member 41, and a second legextending therefrom and connecting to the operation lever 44 so that thecontrol end 442 is biased to be close to the brake assembly 5. The brakeassembly 5 comprises a brake lever 51 including a pivotal portion 511formed on one end thereof, a stop wall 512 corresponding to theoperation lever 44, and a control end 513 formed on the other endthereof. The pivotal portion 511 is pivotally connected to the housing1, and the control end 513 can be operated to pivot the brake lever 51,but not necessary. As the control end 513 of the brake lever 51 ispivoted toward the first end 101 of the housing 1, the control end 442of the operation lever 44 is abutted to be biased to the first end 101of the housing 1 by the stop wall 512 of the brake lever 51. As thecontrol end of the brake lever 51 is pivoted to return to an initialposition (not shown), the operation lever 44 is pivoted to its initialposition by the biasing element 46 so that the operation lever 44 wouldnot interfere with respect to the brake lever 51.

1. A speed control device is operable between a cable-winding operationmode and a cable-releasing operation mode, comprising: a controlassembly including a fixing member, a first engaging mechanism pivotallyconnected to the fixing member, and a second engaging mechanismpivotally connected to the fixing member; wherein the fixing memberincludes a body, a first pawl device selectively engaged with the firstengaging mechanism, and a second pawl device selectively engaged withthe first engaging mechanism, with the fixing member having a firstconnected portion where the first pawl device is disposed to, and asecond connected portion where the second pawl device is disposed to;wherein the first engaging mechanism includes a cable-receiving memberrotatable in a first rotation direction to up-shift the speed and asecond rotation direction to down-shift the speed; wherein the secondengaging mechanism includes a control plate, an engagement plate, and aclutching device, with the control plate having an arm portion, with theclutching device disposed to the arm portion of the control plate andselectively engaged with the first engaging mechanism, wherein theengagement plate includes a first protrusion and a second protrusion,which protrude from an outer periphery thereof, with the first andsecond protrusions correspond to the first pawl device and the secondpawl device, respectively; and wherein the control assembly is adaptedto effect multiple speed change in one stroke of the second engagingmechanism.
 2. The speed control device as claimed in claim 1, whereinthe first pawl device includes a first engaging section and a firstabutted section abutted by the first protrusion, and the second pawldevice includes a second engaging section and a second abutted sectionabutted by the second protrusion, wherein the first engaging mechanismincludes a first toothed section corresponding to the first engagingsection, and a second toothed section corresponding to the secondengaging section, wherein while the second engaging mechanism is notoperated by a user, the first engaging section is disengaged from thefirst toothed section, and the second engaging section is engaged withthe second toothed section.
 3. The speed control device as claimed inclaim 2, wherein the engagement plate includes a hole extendingtherethrough, wherein the first protrusion has a first portion and asecond portion, wherein the first portion and a center of the hole has adistance therebetween smaller than that between the second portion andthe center of the hole, wherein while the first abutted section of thefirst pawl device is abutted by the first portion of the firstprotrusion, the first engaging section of the first pawl device isdisengaged from the first toothed section, wherein while the firstabutted section of the first pawl device is abutted by the secondportion of the first protrusion, the first engaging section of the firstpawl device is engaged with the first toothed section.
 4. The speedcontrol device as claimed in claim 2, wherein the engagement plateincludes a hole extending therethrough, wherein the second protrusionhas a first portion and a second portion, wherein the first portion anda center of the hole has a distance therebetween smaller than thatbetween the second portion and the center of the hole, wherein while thesecond abutted section of the second pawl device is abutted by the firstportion of the second protrusion, the second engaging section of thesecond pawl device is engaged with the second toothed section, whereinwhile the second abutted section of the second pawl device is abutted bythe second portion of the second protrusion, the second engaging sectionof the second pawl device is disengaged from the second toothed section.5. The speed control device as claimed in claim 2, wherein each of thefirst toothed section and the second toothed section is formed on anouter periphery of the first engaging mechanism and includes a pluralityof teeth, respectively, in which each tooth is asymmetric.
 6. The speedcontrol device as claimed in claim 2, wherein the first engagingmechanism includes a retaining toothed section formed on its outerperiphery and including a plurality of teeth, wherein the clutchingdevice has an engaging section formed on one end thereof, wherein whilethe second engaging mechanism 40 is pivoted in the second direction, thefirst engaging mechanism is rotated concurrently due to that theengaging section is engaged with the toothed section to effect speedchange.
 7. The speed control device as claimed in claim 6, wherein thetoothed section is formed on an outer periphery of the first engaging Imechanism and includes a plurality of teeth, respectively, in which eachtooth is asymmetric.
 8. The speed control device as claimed in claim 6,wherein the clutching device has a engaging surface formed on one endthereof, wherein the engaging surface corresponds to a block of thebody, wherein while the second engaging mechanism is pivoted in thefirst rotation direction for the cable-winding operation, the engagingsurface is abutted by the block of the body so that the engaging sectionof the clutching device is disengaged from the toothed section of thefirst toothed member.
 9. The speed control device as claimed in claim 6,wherein the body has a retaining surface formed thereon, wherein whilethe second engaging mechanism is pivoted in the second rotationdirection to a maximum pivotal position, the engaging section of thepawl device abuts the retaining surface of the body to prevent thesecond engaging mechanism from further rotating in the second rotationdirection.
 10. The speed control device as claimed in claim 1, whereinthe second engaging mechanism includes a catching member having a firstemboss formed thereon, wherein the control plate includes an abuttedsurface corresponding to the first emboss of the catching member,wherein as the catching member rotates in the second rotation direction,the control plate is rotated in the second rotation direction due tothat the abutted surface is abutted by the first emboss of the catchingmember.
 11. The speed control device as claimed in claim 1, wherein thesecond engaging mechanism includes a catching member having a secondemboss formed thereon, wherein the engagement plate includes an abuttedsurface corresponding to the second emboss of the catching member,wherein as the catching member rotates in the first rotation direction,the engagement plate is rotated in the first rotation direction due tothat the abutted surface is abutted by the second emboss of the catchingmember.
 12. The speed control device as claimed in claim 1, wherein thefirst engaging mechanism includes a first toothed section, wherein thefirst pawl device includes a first pawl and a first biasingelement,wherein the first pawl has a first engaging section formed onone end thereof, and a first abutted section formed on the other endthereof, wherein the first biasing element includes a first legextending therefrom and connecting to the first abutted section of thefirst pawl, and a second leg extending therefrom and connecting to thebody so that the first engaging section is biased to disengage from thefirst toothed section.
 13. The speed control device as claimed in claim1, wherein the first engaging mechanism includes a second toothedsection, wherein the second pawl device includes a second pawl and asecond biasing element,wherein the second pawl has a second engagingsection formed on one end thereof, and a second abutted section formedon the other end thereof, wherein the second biasing element includes afirst leg extending therefrom and connecting to the second abuttedsection of the second pawl, and a second leg extending therefrom andconnecting to the body so that the second engaging section is biased toengage with the second toothed section.
 14. The speed control device asclaimed in claim 1, wherein the fixing member includes a first retainingunit installed thereto, wherein the first engaging mechanism includes anbiasing member including a proximal end engaging to a limiting portionof the first retaining unit, and a distal end engaging to the firstengaging mechanism.
 15. The speed control device as claimed in claim 1,wherein the second engaging mechanism includes an biasing member whichincludes a proximal end engaging to a limiting portion of the body, anda distal end engaging to the control plate.
 16. The speed control deviceas claimed in claim 1, wherein the fixing member includes a secondretaining unit installed thereto, wherein the second engaging mechanismincludes an biasing member including a proximal end engaging to alimiting portion of the second retaining unit, and a distal end engagingto the engagement plate.
 17. The speed control device as claimed inclaim 1, wherein the second engaging mechanism includes a catchingmember, a operation lever pivotally coupled to the catching member, anda biasing element disposed between the catching member and the operationlever, with the operation lever is biased by the biasing element. 18.The speed control device as claimed in claim 2, wherein a pluralityteeth of the first toothed section has an arrangement like that of aplurality teeth of the second toothed section, wherein the first and thesecond toothed sections have a phase shift therebetween.
 19. The speedcontrol device as claimed in claim 2, wherein the engagement plateincludes a hole extending therethrough, wherein the body includes aholding surface, wherein the holding surface and a center of the holehas a distance therebetween smaller than that of the first protrusionand the center of the hole, wherein the second engaging mechanismincludes a catching member including a second emboss, wherein theengagement plate includes an abutted surface corresponding to the secondemboss of the catching member, wherein as the catching member rotates inthe second rotation direction, the engagement plate is rotated in thesecond rotation direction due to that the abutted surface is abutted bythe second emboss of the catching member, and the first abutted sectionis disengaged from the first protrusion to engage the holding surface ofthe body.